To complete this achievement, you must gather five shards of Caladbolg spread across the four Heart of Maguuma maps. You are given one from Ridhais already, so you just need to collect the remaining four. See the page above for their locations. The reward is an item you will need to return to Ridhais.

To complete this achievement, you must gather eleven motes spread across several maps in Core Tyria. You are given one from Ridhais already, so you just need to collect the remaining ten. See the page above for their locations. The reward is another item you will need to return to Ridhais.

Collect all 5 forms of Caladbolg. There are two ways to do this (one easy, one expensive):

After completing the below Knight of the Thorn achievement, you can return to your Home instance where Ridhais will be waiting. For 1000 Unbound Magic, she will allow you to trade in your current Caladbolg and let you choose another form. Doing this four times, once for each form, will give you the achievement since you just need to unlock each skin. You will only have 1 weapon at the end, though.

You can also create the other four forms on additional characters who have completed Hearts and Minds (and therefore have the Broken Caladbolg). You will need to obtain another Vision Crystal and craft the Spiritwood Scion and Orb of Natural Essence from the recipes earned from those achievements, and going through the last fights as normal. You must use 4 additional characters, and this process will grant you four more Ascended weapons. This is doable on each character that has completed the story.

by speaking to Ridhais in your home instance. Unlike during this achievement, she will not be at the entrance.

Other characters on your account may also complete the story, however the Spiritwood Scion and Orb of Natural Essence must be crafted. Their recipes are automatically unlocked after completing their respective achievements the first time.